John Snow found that the polluted water was _________ for the outbreak of cholera.
| A．to blame | B．to be blamed | C．blamed | D．blaming |
Scientists say it will be five or six years _____ it is possible to test this medicine on human patients.
| A．before | B．that | C．since | D．when |
Youvery fast if you went from New York to Boston in six hours.
| A．should drive | B．must have driven | C．may drive | D．would have driven[ |
They want to make _______ clear to the public that they are doing an important and
necessary job.
| A．this | B．that | C．it | D．what |
_____ the child to bed, she began to correct the pupil’s exercise.
| A．Sending | B．Being sent | C．Sent | D．Having sent |
____ with a difficult situation, Arnold decided to ask his boss for advice.
| A．To face | B．Having faced | C．Faced | D．Facing |